1. Field of the Invention
The invention relates to a side airbag system and a method of manufacturing a side airbag.
2. Description of the Related Art
For example, Published Japanese Translation of PCT Application No. 2003-501303 (JP-A-2003-501303) describes a side airbag. The side airbag includes a cushion and an inflatable tube. The cushion has an inflatable upper chamber and an inflatable lower chamber that are partitioned by a separation panel. The inflatable tube is located adjacent to the cushion and is arranged adjacent to one of a bottom and rear side of the cushion so as to extend the range of at least part of the cushion before the cushion completely inflates by inflation gas.
However, the separation panel described in JP-A-2003-501303 is separately formed from the pieces of base fabric of the airbag, and the peripheral edge of the separation panel is sewed to the two pieces of airbag base fabric. Such work for sewing the separation panel is complicated, so there is room for improvement in terms of mass production of airbags.
In addition, in JP-A-2003-501303, the separation panel has vent holes, and gas is communicable between an upper chamber and a lower chamber through the vent holes. However, with the above structure, it is difficult to maintain airtightness between the upper chamber and the lower chamber, so it is presumably difficult to set an appropriate internal pressure for each chamber.